A sliding screen door is heretofore known as described in Japanese Unexamined Patent Application Publication No. 2002-371776. In the sliding screen door, a screen configured to be free for expansion and contraction in a style of an accordion by means of alternately folding in a reverse direction at numbers of folded portions being in parallel with each other spaced at even intervals is constructed to be free for opening and closing in a style of horizontal pulling in a frame body. In the sliding screen door, in which one end of the aforementioned screen is fixed to a vertical frame member of the aforementioned frame body and the other end of the screen is attached to an operating doorframe for open-and-close operation, which slides along the aforementioned frame body, a wire whose one end is fixed to the aforementioned vertical frame member is horizontally inserted into the aforementioned screen and is drooped in the operating doorframe via a guide member provided in the aforementioned operating doorframe. In addition, a sinker is dangled at a tip end of the wire and a spring member is interposed between the sinker located at a position when the screen is in a condition of being stretched and a contacting portion to be a rising uppermost limit of the sinker.
In the aforementioned known sliding screen door, stretching force that affects the wire only when the screen is in a stretched condition is increased without excessively increasing size of the sinker to be dangled from the wire by means of installing the aforementioned spring member, resulting in suppression for expansion of the screen when the outside force caused by a certain level of strong wind, or the like, is affected to the stretched screen. As a result, both upper and lower ends of screen can be suppressed from a deviation from a horizontal frame member as well as possible. However, since the stretching force of the wire in the stretched condition of the screen cannot be adjusted, even when the stretching force of the wire in the stretched condition of the screen due to installing of the spring member is excessively strong, although the expansion of the screen due to the wind or the like can further be suppressed, not only large operating force is required to move the operating doorframe toward a stretched position for the operation to stretch the screen, but also the operating doorframe moves at an abnormal speed because strong action force of the spring member is added to the action force of the sinker when a locked state of the operating doorframe is released by a latching mechanism. Further, when the stretching force of the wire in a case when the screen is in the stretched condition is excessively weak, although the operating force for the operating doorframe for stretching the screen is sufficiently small, there has been a problem that the expansion of the screen due to the wind or the like cannot be sufficiently suppressed.
In addition, in the aforementioned sliding screen door, since length of the horizontal frame member is determined aligning with an opening of a building where the sliding screen door is installed, it is required that adjustment of the length of the wire can be easily performed in a wide range.